Replacing a collapsed storm drain without major excavations saves money and minimizes traffic
disruption. It also reduces the potential for roadway deterioration and potholes resulting from
large utility patches. Highway maintenance crews in Charlotte, Michigan avoided major
excavations and the problems they cause by repairing a collapsed storm drain under Lansing
Road (I-69 Business Route) using a technology called pipe bursting.
In the July/September 1995 issue of "The Bridge", the Local Technical Assistance Program of
Michigan Technological University explained pipe bursting and described the successful use of
this technology in Charlotte. The article was called "Pipe Bursting: Using Today's Technology
to Solve Tomorrow's Problems."
The Project
The tile storm sewer beneath Lansing Road ran under a busy business district, and Lansing Road
was the only access route to the hospital. When the road began to flood even during moderate
rains, maintenance crews needed to replace 850 feet (259 meters) of 10-inch (25.4 cm) pipe.
Using traditional methods, crews would have had to excavate the entire right lane and close it to
traffic for the duration of the project. To avoid a lane closure, Chad Gamble, the city's
Superintendent of Streets and Grounds, elected to try pipe bursting.
The Technology
British Gas and TRACTO-TECHNIK jointly developed the technology called pipe bursting, which
"allows the replacement of cast iron, clay, cement, and other fracturable pipes with a new main of
the same or larger size for water, sewer, or production lines." Europe and Japan have used the
process extensively, and over 32 million feet (10 million meters) of pipe worldwide have been
replaced using pipe bursting.
Pipe bursting involves digging an entry pit at one end of the failed pipe and running a pneumatic
pipe-bursting tool and an expander into the pipe through the pit opening. The pipe-bursting tool
is a soil displacement hammer fitted with cutting blades. A steel line, attached to the head of the
tool and to a winch on the other end of the pipe, keeps the line tight and helps guide the tool. As
the pipe burster hammers through old pipe, the expander moves broken fragments and dirt out of
the way to make room for new pipe, which is attached to the back of the tool and follows it into
the void. After the new pipe is in place, crews connect service laterals at specified locations.
If necessary, crews can first install a sleeve or carrier pipe and then pull the new pipe through the
sleeve. The extra step is required only when replacement pipe needs to be protected from
fragments of old pipe. Normally this additional precaution is not necessary in storm sewer
replacement.
The Results
With pipe-bursting technology, Charlotte crews repaired the old sewer pipe on Lansing Road
without blocking traffic and without major excavations. Chad Gamble expressed the City's
satisfaction with the process. He said, "In a high traffic area like this, pipe bursting proved to be
the perfect technology. We would definitely use this process again if the situation called for it."
On future projects, he anticipated repairing and replacing segments of pipe, electrical wires,
sewers, and fiber optics using pipe-bursting technology.
